Deliverable 11.2 - Concept and extension of central data node capabilities

This report describes the concepts, approach to design and the demonstrators developed to extend the capabilities of the eLTER Information System (IS) components and especially the Central Data Node (CDN). The pilot workflow implementations are chosen to demonstrate the CDN capabilities, specifically for data from WP4 sources and pilots, VA and CS. The overall architecture of the eLTER IS is described together with detail of the existing individual components. These include existing external components, such as EUDAT B2DROP, that have been used in the prototype phase of the data demonstrators. The extension of the CDN concept is described with the details of the different logical levels of data management required to implement the eLTER RI data governance model. This includes the 4 different levels of data assets that will be managed within the CDN from raw observational data in Level 0 to elaborated data products synthesised with third party data in Level 3. The data types and formats required to support the data assets of the eLTER RI are described at a summary level as the exact specification the eLTER standard measures are yet to be agreed. The overall governance model to support an open data access model is described as supported by the proposed data licensing model for eLTER standardised data products including those synthesised from other data sources (using CC-0 and CC-BY wherever possible with DOI for acknowledgement of originators). Relevant external data services are reviewed for their approach to data service design and relevance to the development of eLTER information services. Detailed review of "sister" RIs such as GBIF and LifeWatch are given, where they are managing similar data types such as biodiversity data, as these services may form part of operational data workflows for eLTER in the future. The details of demonstration workflows that have been developed with eLTER Plus researchers are given to show how a range of different data types will be processed by future operational eLTER RI services. These demonstrators illustrate the iterative prototyping approach used by the project to ensure that the workflows and tools developed match the functional requirements of key users of the RI. The data workflows have been developed using the virtual DataLabs to enable collaborative development between the project team and this is seen as a key success of the demonstration phase of the eLTER IS development, especially with the prototype web interfaces used to show functionality to non technical users. This approach will continue for development of new data workflows supported by the virtual DataLabs infrastructure. The next phase of development is the engineering of the demonstration workflows into operational eLTER RI services. This will require moving from the prototype specification of the data workflows to a final architectural specification of the data types and web service interfaces of the eLTER IS components (and especially the CDN) for use by external researchers and collaborating RI service developers. This phase will extend but not replace the iterative prototyping approach already successfully used for functional development and reported in this deliverable.